1. Field of the Invention
This invention relates to a paper feed controlling device which is used in a laser printer, for example.
2. Description of the Prior Art
In recent years, laser printers have been prevailing as means for printing character information and image information. These laser printers are adapted to select the size of recording paper from a plurality of sizes in conformity to a given size of images to be printed. Generally, the size of recording paper to be used is freely set to fit the size of a given image by a manual operation performed by an operator or in accordance with a command issued from a host computer to which the laser printer is connected. After this setting is completed, recording papers of the size so set are fed to the laser printer and images of the matching size are printed therein on the recording papers. Unlike the laser printers of the type adapted to feed recording papers of a size conforming to the size of recording paper which has been set as described above, there are laser printers of the type endowed with the function of matching the size of recording paper with the size of an image about to be printed. The laser printers of this type are so adapted as to recognize the size of a recording paper about to be fed after the feeding of this recording paper has been completed.
When a laser printer which is adapted to recognize the size of a recording paper after the feeding of this recording paper has been completed is operated at a relatively slow printing speed, since the feeding of a second recording sheet is effected after the size of the first recording paper has been recognized, the possibility that the relevant image is accidentally printed on a recording paper of a size different from the size of the image could occur on only one recording paper at most. When this laser printer is operated at a speed faster than the ordinary printing speed, namely at a speed enough to attain the so-called maximum throughput, since the feeding of the second recording paper is initiated before the size of the first recording paper already fed is recognized, it is not impossible that an image will be printed on two recording papers of a size not matched with the size of the image.